New top end recomendations??...

If you tell us what you have now I am sure that you will get more recommendations then you can possibly use, but it will be fun to consider them all.

Is this a stock '71, '72, '73, '74?

oh sorry about that... it's a 72' 351 CJ stock accept intake/carb/headers... I originally thought the block was 60 over, in which case I was gonna' bump the comp and put a cam/heads/nitrous plate and wait for it go south while I built another engine. Since the block is only 30 over, and is the original, I think i will be a bit more conservative. I will still build a hot rod engine later or get a crate engine but, all things considered this engine can be warmed over and used for years.... I see a few guys like the EX284 or 274, that's about what I'm looking for also with the heads/intake to wake this motor up a little ( while still being fairly careful w/it, not too much abuse)... Thanks...

I'm running the Comp. EX 284 cam. With iron closed chambered heads, TFC intake, 735 Holley. I've been very happy with the this Cam. Has a nice lope to it. Probably get better low end torque with a dual plane manifold, but I like the TFC high rise polished looks!

yeah, so far it looks like the EX284/closed heads/stainless valves is a nice set up...

Can't tell you if mine is "better" than Cuvee's, whatever better means, but I'm running a CompCams 282S, Aussie closed chamber heads, Weiand Xcelerator intake... I really like it. Heads and intake were extensively worked, carb blueprinted, etc.

It's a completely different motor than a stock Cleveland... I've got a 6500 rpm rev-limiter in the MSD box and it's still pulling happily when the rev limiter kicks in. I've had a small handful of "standard" Clevelands, and they all pretty much ran out of air above 5500...

My experience w/this engine is just as you describe Charlie. Not much after 5300. Those aussie heads sound nice. I think this week I will ebay away some of my bike stuff and learn to properly ID closed heads and then check around locally. Are you guys still on stock compression with those cams??... 8.0, 8.5, 8.8 ??...

quote:

Originally posted by PLT-1:
My experience w/this engine is just as you describe Charlie. Not much after 5300. Those aussie heads sound nice. I think this week I will ebay away some of my bike stuff and learn to properly ID closed heads and then check around locally. Are you guys still on stock compression with those cams??... 8.0, 8.5, 8.8 ??...

This engine is my fifth in a Pantera. It's the first the pulls past that 5500 limit. And it doesn't just creep past, it really seems like a different type of motor. I'd even describe it as "rev-happy".

I'd assume it's the cam that does that, although it is perhaps airflow (heads, etc).

For general info, I'm running about 10.3:1 compression.

My engine was spec'd component by component by Dan Jones, who sometimes posts here.

The stock exhaust system is a problem, if you still have a stock exhaust system it has to go. A Hall GTS system is a minimum upgrade, or PIM Big Throat headers with Magna Flow mufflers may be worth your consideration. Beyond that there's the system built by Pat Mical. The stock exhaust system will hold back any other performance mods you would make to the motor.

If you want the motor to look stock or for some other reason want to stay with iron heads I am in full agreement with Charlie, up to 400 bhp can be made with the Aussie heads (small port) from their 302 Cleveland motor. Throw on the Edelbrock Performer 2V manifold and rock & roll. The Performer can be painted blue & look basically stock. These heads can definitely stand some porting and larger intake valves (2.08" - 2.10") to realize their full potential. The closed combustion chambers of these heads are so small that they raise the compression ratio too much with flat top pistons, they are a great match however with the factory dished pistons.

The power characteristic of the small port (2V) heads is a little more sedate (more linear) than the power characteristic of 4V heads, which have a mid-range rush like the after-burners of a fighter jet kicking-in. Some people like the "small port" power delivery better. As I get older I wonder if the 2V power delivery wouldn't be better for me too. This is not to say that 4V heads can't have good low rpm power too, they can, its a matter of avoiding "over-camming" the motor.

If you choose to stick with 4V heads, the best versions to hunt down are the 1970 castings, D0AE. They will give you 10.0:1 compression ratio with factory flat top pistons. The 1971 catings D1AE, will yield 9.7:1 compression ratio with factory flat top pistons. For intake manifolds the Holley Strip Dominator is the king of the single plane manifolds, only available used. They seem to go for about $400 on ebay. After that the Edelbrock Torker is a second choice in single plane intakes. The Blue Thunder is the king of the 2 plane intakes, and the Ford two plane Holley flange intake in either iron (D0AE-L) or aluminum (D1ZX-DA) would be my second choice.

For camshafts I strongly recommend a low overlap camshaft (60 degrees or less) ground on 112 degree or 114 degree lobe centers. About 275 to 280 degree intake duration and 10 degrees more exhaust duration. Or about 285 degree duration single pattern cam.

For a carburetor to feed a stock displacement Cleveland with a dual plane manifold you want a carb rated 735/750/780 cfm rated at 1.5" mercury depression, dry flowed, like Holley. The Torker (single plane) with a 650 cfm carb is a popular set-up.

cowboy from hell

Wow!, Thanks CFH... I am confused about the proper way to ID my heads?.. I have the "4" on each corner but thats all i can find?... I can't see any "D" codes under the valve covers. I did find time stamps and "OH28"??.. Are the D codes on the piston side??... Thanks...

Unfortunately the casting numbers are located onthe bottom side of the intake ports, see the pic below.

The 0H28 number is the cating date and equates to August 28, 1970. Since August 28 is after July 1 the heads were cast during the 1971 production year, I would guess they are D1AE castings.

It would be possible to mill the 1971 heads to yield the same compression ratio as the 1970 versions, and/or depending upon the cam you choose, 9.7:1 compression ratio may be just fine anyway. It seemed as though you were in the market for heads, so my original thought was to merely point out which iron castings are the most desireable.

cowboy from hell

Thank you very much!!... I pulled the heads this morning and indeed (as usual) you are correct. I located the numbers and they are D1AE castings. So, it appears I have 4V large port, large valve, closed heads??... 9.7 sounds great to me??. Please clarify the 9.7? Is it possible to easily raise this comp. to 9.7 or is it possible this motor (engine) is rated at 9.7??... I think/it sounds like if I rework these heads I will be just fine. I never thought I would have decent heads to start with, (not my luck). If this motor is 9.7 that will be perfect. I can wake this baby right up... Thank you very much for the help and advice!!...

Which ever way you go, get rid of the stock two peice valves!

Those 1971 heads with flat top pistons were rated by Ford in their literature at 10.7:1. Many people are under the assumption that this is gospel, and why not? But in reality Ford either lied about this, or an engineer did the math wrong, its actually exactly one full point lower than that, it is beyond a shadow of a doubt 9.7:1 with a standard bore. If your motor is 0.030" over then of course its a bit higher than that.

While this motor is apart, I advise you to spend money on the following work:

(1) Rebuild the heads, replace all the valves with good quality "single groove" stainless steel valves, and install the good bronze valve guides
(2) Install Ross fordged flat top, round skirt pistons (greater compression height than stock)
(3) Replace the rod bolts with ARP hardware
(4) Buy a Romac balancer
(5) Have the reciprocating assembly dynamically balanced
(6) Install tough bearings like Clevite 77. Clearances: main bearings = 0.0020" - 0.0025" ... rod bearings = 0.0025" - 0.0030"
(7) Buy a Roll Master timing set (steel gears, 9 keyway crank sprocket)
(8) Install tappet bore bushings
(9) Buy a high capacity, baffled oil pan (Armando)
(10) Buy the proper 351C specific thermostat (Robertshaw 333 series)

The Ross forged pistons plus D1AE heads will set the static compression at 10:1. The round skirts of the Ross pistons will help prevent cylinder wall cracking, one of the Cleveland's recurring issues. The remainder of the work suggested is also aimed at resolving recurring issues and making your motor more durable. Please do not run that motor with a 30+ year old dampener. That is a problem waiting to happen.

Take Curts advice about the valves very seriously, the stock valves like to drop the heads, the picture below is an example of the damage.

Yikes!! that looks bad!.. who should I contact about the correct valves for these heads?... who do you like for SS valve sets?... Thank you very much for the parts list and your expert advice!!

Absolutely the best top end upgrade for a street motor would be a pair of CHI heads.

Details are available at www.chiheads.com

Remember these heads absolutely have dominated the Engine Masters Competition every time the rules permitted their use. They have a variety of intake port sizes to choose from depending on the displacment / rpm / hp, etc of your desired build.

They offer both dual and single plane manifolds to match. Additionally they offer everything you need to use the heads on both Cleveland(Standard 9.2 and 400M) and Windsor (9.2 and 9.5 deck heights) blocks.

I found these Manley Race Master valves, they have "Severe Duty" valves also... 14 bucks and 23 bucks respectivley... I'm still lookin"...